2017 NEC grounding electrode system at ground mount

[SolarAlternativesDesign]

Earlier I had the impression that with 2017 NEC the requirement for a grounding electrode at ground mount arrays would be eliminated with the deletion of 690.47(D), but looking at the new 690.47(A) I think the requirement is increased. A ground mount racking system is a structure and requires a grounding electrode system installed in accordance with Part III of Article 250. The relatively lax requirements of 250.54 Auxiliary Grounding Electrode, which I think satisfied 690.47(D), don't appear to suffice for the 690.47(A) GE, and it appears that the GE installed at the array must be bonded with the rest of the premises grounding electrode system. Am I correct? I was just surprised.

 

[jaggedben]

I agree. So you have to drive two ground rods now instead of one, unless your pylons qualify. Take one for the team: us rooftop guys no longer have to put ugly and unnecessary conduits down the side of people's houses.

 

[jaggedben]

Small clarification:

For a ground mount array you do not need to bond to the grounding electrodes at another structure other than via the EGC that you're already required to run with the conductors.

Basically ground mount arrays are now treated no different than other separate structures in 250.32.

 

[SolarAlternativesDesign]

Thank you very much for that clarification. I was looking at 250.50 as if all GEs in the whole site had to be bonded together.